One Way to Recharge Alkaline Batteries
It says it right on the side of every alkaline battery – do not attempt to recharge. By which of course the manufacturer means don’t try to force electrons back into the cell. But [Cody] figured he could work around that safety warning chemically, by replacing the guts of an alkaline dry cell.
The batteries in question were certainly old, gnarly looking, and pretty dead – [Cody] barely got a reading on his multimeter. As you can see after the break, he cleaned off the exterior corrosion and did a quick teardown of the dry cells, removing the remains of …read more
96 MacBook Pros: Most Expensive Server Rack We’ve Ever Seen
Ever see a standard server rack stuffed full with 8-dozen MacBook Pros? Well now you have.
Now before the torrential downpour of anti-Mac comments come, this actually has a purpose. No seriously. Besides, what company in their right mind would spend that much money on a rack full of paperweights? Kidding.
[Steve] works for a company that designs electronics, and for a particular launch they needed to perform a lot of testing — using MacBook Pros. There are ways he could have emulated OS X on a much cheaper hardware setup, but the whole point was to test the product …read more
Find and Repair a 230kV 800Amp Oil-Filled Power Cable Feels Like Mission Impossible
How do you fix a shorted cable ? Not just any cable. An underground, 3-phase, 230kV, 800 amp per phase, 10 mile long one, carrying power from a power station to a distribution centre. It costs $13,000 per hour in downtime, counting 1989 money, and takes 8 months to fix. That’s almost $75 million. The Los Angeles Department of Water and Power did this fix about 26 years ago on the cable going from the Scattergood Steam Plant in El Segundo to a distribution center near Bundy and S.M. Blvd. [Jamie Zawinski] posted details on his blog in 2002. [Jamie] …read more
The Factory of the World – Hackaday Documentary on the Shenzhen Ecosystem
When it comes to manufacturing, no place in the world has the same kind of allure as the Pearl River Delta region of China. Within just an hour-long train ride, two vastly different cultures co-exist, each with its unique appeal that keeps attracting engineers, entrepreneurs, and hustlers alike. On the mainland side, cities like Shenzhen and Guangzhou bring the promise of cheap components, low-cost contract work, and the street cred of “having done the Shenzhen thing.” And on the island, the capitalist utopia called Hong Kong glows with all of its high finance and stories of lavish expat lifestyles.
As …read more
Retro TO-3 Switching Voltage Regulator
Restoring old gear often means replacing unavailable parts with modern equivalents. [Alex Eisenhut] needed to replace some old TO-3 voltage regulators and decided to make an authentic-looking switching power supply replacement. These three pin metal cans were very common, especially the LM340 5V regulator which was, of course, a linear regulator. Today, you are more likely to see a 7805 in a TO-220 case or something surface mount for a comparable linear regulator.
As you might expect, the board uses surface mount components. [Alex] used Mill Max machine pins to match the original regulator footprint and calls the regulator Ton3y. …read more